Pickups are a core part of a guitar’s tone – they also happen to be a common victim of unwanted noise. Because of this, manufacturers have developed several ways to combat these issues. One such way is known as wax potting. This technique essentially consists of dipping the pickup into hot wax (although other substances such as nitrocellulose lacquer or epoxy resins can also be used). In fact, a good chunk of pickups made today feature wax potting. Below, we take a look at how wax potting combats noise along with the potential cons this technique can have on your tone.
If you've ever experienced a high-pitched howl when trying to play your guitar at higher volume levels – especially when using a distortion pedal or an overdriven amp – it's more than likely being caused by microphonic noise (which is different from EMI issues and mains hum). To understand exactly what’s going on here and how wax potting helps, we need to take a quick look at how a pickup works.
As far as the components go, a guitar pickup actually consists of a pretty simple design; they are comprised of a coil of copper wire wrapped around a magnetic component, held together by a bobbin. When the coil is wrapped around the magnet, it creates a magnetic field, and when you pluck a string, it causes a change in the field that is translated into a current. This current then travels through all the components of your signal chain until it reaches your guitar speakers where it is given off as sound.
In this entire chain, the only parts that should be moving are the strings and the speakers. But when you experience microphonic noise, something else is moving too – the pickup coil. Although pickup coils are wound pretty tight, they can still vibrate at loud volume levels. And it is this vibration that causes the microphonic noise.
How Wax Potting Helps
As you might have guessed, the way manufacturers deal with coil movement and the microphonic noise it can create is by dipping their pickups in molten wax (or other substances that can solidify quickly and not melt easily). The wax keeps the coil fixed in place by filling in all the little gaps between the windings. If the pickup features a cover, manufacturers might also dip the pickup a second time in order to fill in the gaps between the bobbin and the cover. Now that the coil is unable to move, it essentially eliminates the propensity for microphonic noise (although other noise issues such as 60-cycle mains hum and EMI could still cause problems). Check out the quick video below for a look at how Fender pots their pickups:
Potential Effects On Tone
Despite the advantages of eliminating microphonic noise, there are a number of players that prefer their pickups without the wax. In fact, many even go as far as removing the wax themselves if a certain set they like is already potted. They feel as though the wax makes the pickup lose some of its liveliness, dulling out the response. Of course, there are also many players who feel that it either doesn't make any noticeable difference or if it does, it's minor and not enough to outweigh the benefits of wax potting. Personally, I see this debate similar to that of covered versus uncovered humbuckers. There might be a slight tonal difference but by the time you add in effects, gain, and your amp's own tone, it will probably be a non-factor.
If you have a set that has not been waxed and would like to do it yourself, the process is not too complicated, as you can see in the video below ...
Pickup Wax Potting:
Of course, if you're not comfortable messing around with your guitar's pickups, it's best you leave it to a professional or invest in a new set. Many of today's modern pickups come wax potted and should not be affected by microphonic noise. If you're in the market for pickups, make sure to take a look at our selection by using the link below. And if you have any questions regarding the purchase of a certain pickup or any other piece of gear we carry, don't hesitate to chat with one of our friendly PAL pros by using the live chat feature below or by calling us toll-free at 1 877-671-2200!
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